lib/email/message_builder.rb uses the forum’s SiteSettingtitle as the email sender.

def site_alias_email(source)
"#{SiteSetting.title} <#{source}>"
end

We have some customers using characters in the title that are not allowed per RFC2821/RFC2822, causing the email to be rejected by Mandrill.

Also, some users use ‘Welcome to XYZ community’ as a forum title, causing email digests to be sent out with the sender ‘Welcome to XYZ community digest’, where ‘XYZ community digest’ would make more sense.

How about making a separate site setting for the title when used as an email sender in conjunction with notification_email ?

I see. @neil can you add this to your list? If users can enter crazy characters, they will. Not sure what the best course of action here is, but broken emails will lead to support topics, and support topics lead to hair loss.